Due to the depth of the snow in which snowblowers are usually used, many snowblowers are self-propelled. Snowblowers can be hard to manipulate within deep snow because of the weight of the machinery. The deeper the snow is, the harder it can be to maneuver the snowblower. Self-propelled snowblowers allow advancement and regression of the snowblower at least partially under the power generated by its engine. Self-propelled snowblowers can be relatively easy to use as compared to non-self-propelled snowblowers. Through the use of self-propelled mechanisms on snowblowers, a user can devote relatively less energy in advancing the snowblower forward and concentrate more energy on steering.
Typically, self-propelled snowblowers have an engine, a pair of drive wheels, an auger, and a discharge chute. The engine provides power to all power-requiring components of the snowblower, which include the drive wheels and the auger. A typical method used to transfer power from the engine to the wheels is using a friction drive or a chain drive. For either the chain drive or the friction drive, a user can engage the drive by, for example, depressing a drive lever located on the handlebar of the snowblower.
To turn the snowblower when the self-propelled drive of the snowblower is activated, the speed of rotation of the individual wheels can be changed. For example, the use of two clutches, one associated with each wheel of a two wheel snowblower, can be selectively operated by a pivoting control on the handle so as to allow for power steering of the snowblower. The drive system of such a snowblower can include an engine, a snowblower clutch, a drive clutch, and a final drive including two independent wheel clutches. The final drive can have left and right wheel clutches intermediate an input gear and the left and right wheels. The input gear can be engaged by a chain. The wheel clutches can be engaged such that the wheels are driven by the chain. Left and right controls can be used to engage and disengage the respective clutches. For example, upon movement of a control for the left side, the left wheel clutch can be disengaged. Since at this time, power will only be applied to the right wheel, the snowblower will turn left on forward motion. On return of the control from the left to its neutral position, the left wheel clutch is again engaged and the snowblower returns to movement in a straight direction. With the clutches, the wheels can still rotate after disengagement of the respective clutch, thereby widening the turn.
In other self-propelled snowblowers, individual brakes can be used to turn the snowblower. An individual brake can be associated with each wheel of a two wheel snowblower. The brakes can be selectively operated to stop rotation of the associated wheel to cause that wheel to stop and the snowblower to turn in the direction of the stopped wheel. With the brakes, the drive system still tries to drive the wheels even after engagement of the respective brake. This makes braking harder and can widen the turn.
Therefore, an improved drive assembly for both of the driven wheels is provided that can both brake and clutch the respective wheels to provide independent control of both wheels of a snowblower to turn the snowblower during operation.